Under federal law, 18 U.S.C. § 922(g)(3), unlawful users of marijuana are generally barred from possessing guns, and this includes medical users (since federal law has no medical marijuana exemption). Does this preempt a state concealed carry licensing law that has no exception for medical marijuana users? No, said the Oregon Supreme Court: The licensing law doesn’t create an affirmative obstacle to the federal marijuana ban, but simply means that Oregon isn’t going to help enforce that ban. Oregon set up the general ban on concealed carry; it is now free to relax that ban by allowing licensing, and it doesn’t matter that some of the licenseholders are barred by federal law from possessing guns — let the federal government enforce its own gun ban if it wishes, but Oregon has no obligation to assist with that.